Electronic regulator



Aug. 6, 1940. F. H.' GULLIKSEN 2.2101

ELECTRONIC REGULATOR Filed April 7; 1957 v f E k INVENTOR H F 012 H Gz/Z/z'ksen.

m BY

Patented Aug. 6, 1940';

Emo'rnomo rmoom'ron Finn H. Gulliksen, Wilkinsburg, Pa., asslgnor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application April 7, 1937, Serial No. 135,415;

13 Claims. (oi. 171-119) My invention relates to electronic regulators, and is particularly adapted for use in controlling an electrical quantity, such as voltage, of an alternating current circuit.

One object of my invention is to provide an electronic regulator that is reliable and accurate in operation and that is rapid in response to changes in the regulated quantity;

Another object of the invention is the provision of an electronic i'egulatorhaving a detector circuit that is quick in its initial response to variations in the regulated quantity from the desired value and that is thereafter recalibrated to insure an accurate final adjustment,

A further object of my invention is the provision of an anti-hunting circuit that is promptly responsive to variations in the regulated quantity.

Other objects andadvantages of my invention will appear from'the following description of one preferred embodiment thereof, reference being had to the accompanying drawing, in which Figure 1 is a diagrammatic view of apparatus and circuits illustrating a preferred embodiment of the invention, and I Fig. 2 illustrates curves showing certain relationships between component voltages of the system.

Referring to. the drawing, a machine i, such as an electric generator, is provided with an armatime winding 2 for supplying alternating current energy to a circuit represented by conductors 3, 4, 5 and with a field winding 6 supplied with energy from an exciter generator I having an armature winding 8 and a field winding 9. The field winding 9 is supplied with unidirectional current from an alternating current source, such as conductors 3 and 5 through conductors l2 and I3, and a transformer M as supplied by the tube rectifiers l6 and I7.

The current output of the rectifiers l6 and I1 is controlled by a detector tube l8 and an amplifying or control tube I9 'in accordance with the voltage between conductors 3 and 5 are supplied to the primary winding 22 of a transformer 23 through conductors l2 and I3. The energizing winding for the exciter field 9 extends from the central point of the transformer secondary winding l5, by conductor 24 through the winding 9, switch 25, conductor 26, and cathodes 21 of tubes I6 and I1 respectively, and the anodes 28 thereof,

' to the opposite terminals .of the winding l5, the

tubes l6 and I! providing full wave rectification of the current supplied by the transformer l4 ina well known manner. A control potentialEo'that is determined by tubes I8 and His supplied to 1 the grids 28 of tubes ii and I! to govern the current output through these tubes to the field winding 9. The voltage E is made up of two components E1 and E2, E1 being the voltage drop across a resistor 3i, and E: being the voltage drop between a terminal 33 and an intermediate point 34 of a. resistor 38 that is supplied with uni-directional current through a full wave rectifier 36 from a transformer secondary winding 31 that is responsive to variations in the voltage between the power circuit conductors 3 and 5. The grid circuit of tubes l6 and I1 extends from the oathodes 21 through conductor 26, theresistor'iil, the portion of the resistor 35 that is between points 33 and It, conductor 38, and alternate halves of the secondary winding 39 of a phase shifting transformer to the respective grids 29 of the tubes. [8 and it; An alternating current wave the primary winding 45, the other end of the transformer primary winding 15 being connected to-the mid-point 58 of the winding 42.

The primary control of the grid circuit of the rectifier tubes l8 and ii is the amplifying or control tube l9 having a cathode, 4? that is connected to the negative terminal 48 of the resistor 35,. a heating element 49 that'is supplied with current from the winding 52 of the transformer 23, acontrol grid 53, an anode 54, and an anode grid 55 that is connected by conductor 56 to an intermediate point 51 on the resistor 35. .The

anode 54 is connected by conductor58 through the resistor 30 to the positive terminal of the resistor 35.

The tube II is a two-element tube having-an anode 58 that is connected through a resistor to the positive terminal 33 of the resistor 35 and a fllament cathode 62 that is connected to be heated from a transformer winding 63 in accordance with the voltage E4. that varies with the regulated voltage Enbetween conductors l2 and IS. The cathode 62 is also connected through a. junction point with the cathode 41 of the tube l9'and to the negative terminal 48 of the resistor 35. The voltage between the cathode 41 and the control grid" of the tube 1 9 is composed of three plied with alternating voltage from a transformer winding Bl .thatvaries in accordance with the regulated voltage ER, and the voltage E1 being that developed inan anti-hunting resistor 68. The circuit from the cathode l! including these voltage components is traced through conductor H, Junction point t6, conductor i2, through tube It, conductor 13, condenser 65, conductor i l and resistor 68 to the control ,grid 53.

The voltage across the anti-hunting resistor 68 is determined by an anti-hunting network to the terminals Ti and E8 of which a unidirectional voltage is supplied through a full-wave rectifier I5 from the transformer winding 76 that varies in accordance with'the regulated voltage Ea. A resistor 19 and condenser 8| are connected in parallel between the terminals 11 and E8 of the network to form a filter circuit in a well known manner. The circuit through the network between the terminals i1 and 18 extends through a reactor 82, resistor 83, to a junction point 84, thence through two branch circuits, one of which includes a condenser 85, and the other of which includes acondenser 86 and the resistor 68 in series, to the terminal 11. When the regulated quantity En is at any constant value, a constant charge exists on the condenser 85 determined by the voltage between terminals Ti and 78, the charge being constant so that no current flows through the anti-hunting resistor as and the potential drop thereacross is zero.

When the generatori's' started, the switch 26 in the exciter generator field winding circuit may be moved to engage the contact 8'! to temporarily energize the exciter field winding from the armature winding 8 through a resistor 88 until the machine has built up a substantial voltage, after which the switch member 26 is moved to its illustrated position. Inthis position, field current fiows from the transformer winding is through the tubes l6 and l'l which rectify alternate half cycle waves as controlled by the potential of the grids 29. Assuming that the regulated voltage ER is constant at its desired value, the unidirectional voltage from the rectifier it that is impressed upon the resistor 35 will be constant and the voltage component E2 will be constant. The voltage E4 determining the heating of the detector tube cathode 62 is also constant so that the current flow through the tube and the voltage drop E5 thereacross is constant. Likewise, the voltage componentEe that is determined by the .voltage Ea through rectifier ,66 isconstant and the voltage component E7 is zero, as above explained, thus permitting a constant current to flow through the control tube l9 causing a constant voltage drop E1 which combined with a constant component E2 supplies a constant output control voltage E0 for controlling the rectifier tubes l6 and I1.

If, for example, the voltage-Ea now drops,

whichmight be caused by a sudden increase in load on the generator I, the voltage component Es correspondingly. drops. As above noted, the voltage Ea between the cathode l1 and control grid 53 of the tube I9 is made up of three components E5, E6 and E1. The component E1 is zero at the initiation of a change in the voltage ER and the component E5 is substantially constant for a short time interval thereafter owing to the iact that an appreciable time is necessary for a change in the heating of the cathode 62 after a change in the voltage E4 as indicated by the curve E5 in Fig. 2. Therefore the initial change in the regulator voltage ER, which efiects a correspondingly sudden decrease in the voltage component Es causes the potential of the control grid 53 to become immediately more positive, permitting a greater flow of current through the tube l9 from the positive terminal 33 of the resistor 35 through conductor'al, conductor 58, anode and cathode 5d and 31, and conductor H to the nega-.

regulated voltage Ema wave of stabilizing volt age component E7 (see Fig. 2) is developed across the resistor 68 in a direction to ,make the grid 53 still more positive for a short duration of time so that the increase in the voltage Ea, which is the sum or the voltage components E5, E6 and E1 is increased, thus making the grid more positive to increase the current fiow therethrough and cause the voltage component E1 to vary as shown in Fig. 2, to increase the current flow through the tubes l6 and I1 and the exciter field winding.

The curve E1 in Fig. 2 shows the general nature of the voltage change across resistor 3i during the initial part of the regulating action. It will be noted that the voltage E2 makes a rapid change influenced in part by the stabilizing volt age wave E: which gives a temporary influence to the shape of the curve.

The explanation of the voltage wave E1 will be readily understood in that as the potential ER is reduced the unidirectional potential across terminals TI and 18 from the full-wave rectifier is correspondingly reduced, thus reducing the potential across the terminals of the condenser 85. This causes a circuit to flow from the condenser 85 through the condenser 86 and resistor 68 to the terminals TI and 18, thus making the left-hand or grid end of the'resistor 68 more positive than the terminal 11 so long as this discharging current flows from the condenser 85.

After a, short time interval during which the corrective action occasioned by'the change in the valueof the voltage component E1 is under way, the decrease in the heating of the cathode 82 in response'to the decrease in the regulated voltage Ea causes the current flowing through the tube l8 to decrease, thus increasing the voltage component E5 which has the eifect of increasing the potential on the control grid 53 of the tube l9 to recalibrate this tube for the new load condition requiring an increased value of E0 inorder to maintain the regulated voltage Ea constant at 'the new generator load. It will be noted in difi'erence between these two quantities. Thus, an

increase in the voltage component E5 raises the potential of the control grid 53 and a decrease in the control potential Es raises the potential of the control grid 53.

1 rent through the rectifier tubes i6 and H.

An increase in the regulated voltage Ea causes the reverse operation of the several component parts of the detector circuit to decrease the voltage E and correspondingly the excitation cur- For example, upon an increase in the regulated voltage Ea, the unidirectional output voltages from the full wave rectifiers 66, 15 and 36 correspondingly increase, as does the voltage component E4 for controlling the heating of the cathode 52 of the detector tube 98. The initial action of the increase in the voltage components Es lowers the potential of the control grid 53, since the potential E across the detector tube 58 is substantially constant for a short period of time. The fiow of current to the condenser 85 to increase the charge will cause more current to fiow through the tube [all it, thus decreasing the voltage drop thereacross and causing the voltage component E5 to correspondingly decrease and thus recalibrate the tube M for the new required values of E5 and E6.

Many modifications may be made in the apparatus and circuits illustrated and described within the spirit of my invention. I do not wish to be limited otherwise than by the scope of the appended claims.

I claim as my invention:

1. In a regulating system, an alternating current power circuit, a dynamo-electric machine having a field winding for supplying energy to said power circuit, means for supplying a unidirectional current from said power circuit to said field winding comprising a grid controlled rectifier tube, means for controlling the output of said rectifier tube comprising a detector tube having an anode and a filament cathode sensitive to the regulated quantity, a grid controlled amplifier tube governed thereby, and additional means sensitive to variations in the regulated quantity for also influencing said amplifier tube.

2. In a regulating system, an alternating current power circuit, a dynamo-electric machine having a field winding for supplying energy to said power circuit, means for supplying a unidirectional current from said power circuit to said field winding comprising a grid controlled rectifier tube, means for controlling the current output of said rectifier tube comprising a grid governed control tube, means for controlling the control tube grid voltage comprising a filament cathode detector tube that is sensitive to variations in the regulated quantity, and means for introducing a voltage component into the grid circuit of said control tube that varies more promptly with variations in the regulated quantity than does the detector tube.

3. In a regulating system, an alternating current' power circuit, a dynamo-electric machine connected to said power circuit and having a field winding, grid controlled rectifier means for supplying a unidirectional current to said field winding, means for controlling the current output of said rectifier means in response to a regulated quantity comprising a grid controlled tube, means for controlling the grid potential of said tube including a plurality of means for introducing control potential in series in the grid circuit of said tube that are sensitive to the regulated quantity and that are characterized by different rates of response to variations in the regulated quantity.

4. In a regulating system, an alternating current power circuit, a dynamo-electric machine connected to said power circuit and having a field winding, grid controlled rectifier means for supplying a unidirectional current to said field winding, means for controlling the current output of said rectifier means in response to a regulated quantity comprising a grid controlled tube, means for introducing a plurality of voltage components into the grid circuitpf said tube, one of said components varying promptly with variations in the regulated quantity in a direction to effect a correction thereof, and another of said components varying more slowly with variations in the regulated quantity in a direction to effect a correction thereof.

5. In a regulating system, an alternating current power circuit, a dynamo-electric machine connected to said power circuit and having a field winding, grid controlled rectifier means for supplying a unidirectional current to said field winding, means for controlling the current output of said rectifier means in response to a regulated quantity comprising a grid controlled tube, means for introducing a plurality of voltage components into the grid circuit of said tube, one of said components varying promptly with variations in the regulated quantity in a direction to eifect a correction thereof, another of said components var'ying more slowly with variations in the regulated .quantity in a direction to effect a correction thereof, and another of said components efi'ecting a temporary impulse in a direction to effect a correction in the regulated quantity.

6. In a regulating system, an alternating current power circuit, a dynamo-electric machine connected to said power circuit and having a field winding, grid controlled rectifier means for supplying a unidirectional current to said field winding, means for controlling the current output of said rectifier means in response to a variation in the regulated quantity comprising a grid controlled tube, means responsive to the regulated quantity for controlling the grid potential of said tube, and means sensitive to changes in the regulated quantity for introducing a surge potential of short duration into said grid control circuit in a direction to increase the rate of correction or the regulated quantity.

'7. In a regulating system, an alternating current power circuit, a dynamo-electric machine connected to said power circuit and having a field winding, grid controlled rectifier means for supplying a undirectional current to said field winding, means for controlling the current output of said rectifier means in response to a regulated quantity comprising a grid controlled tube, means for controlling the grid potential of said tube including full wave rectifying means responsive to the regulated quantity and a cathode filament iii) Y the current output of said rectifier means, means for controlling the grid potential of said tube including a plurality of means for introducing control voltage components in series in the grid circuit of the tube, one of said means introducing a voltage component that is promptly responsive to variations in the regulated quantity, and another of said means introducing a voltage component that is controlled by said'detector tube.

9. In a regulating-system, an alternating current power circuit, a dynamo-electric machine connected to said power circuit and having a field winding, grid controlled rectifier means for supplying a unidirectional current to said field winding, means for controlling the current output of said rectifier means in response to a regulated quantity comprising a grid controlled tube, and a cathode filamentdiode detector tube sensitive to the regulated quantity, means for controlling the grid potential of said tube including a plurality of means for introducing control voltage components in series in the grid circuit of the tube, one of said means introducing a voltage component that is promptly responsive to variations in the regulated'quantity, another of said means introducing a voltage component that iscontrolled by said detector tube, and another of said means introducing a voltage component of short duration that varies in direction and degree with the change in the regulated quantity and in a direction to increase the rate of response in the correction of the regulated quantity.

10. In a regulating system, an alternating current power circuit, a dynamo-electric machine connected to said power circuit and having a field winding, grid controlled rectifier means for supplying a unidirectional current to said field winding, means for controlling the current output of said rectifier for controlling the excitation of said dynamo-electric machine comprising a cathode filament diode detector tube that' is *responsive to the voltage of said alternating current power circuit-and a grid controlled amplifier tube, a plurality of means for introducing voltage components in series in the grid circuit of the amplifier tube comprising means for introducing a voltage component that is responsive promptly to variations in the regulated quantity, means sensitive to changes in the regulated quantity for introducing a surge potential of short duration in a direction to increase the rate of correction of the regulated quantity, and nieans including a cathode filament diode detector tube responsive to the regulated quantity for gradually recalibrating the amplifier tubeafter the initial correction in the regulated quantity.

11. In a regulating system an alternating current power circuit, a dynamo-electric machine connected to said power circuit and having a field winding, grid controlled rectifier means 1 for supplying unidirectional current to said field comprising means for introducing a voltage component into the grid circuit of said amplifier tube that is promptly responsive to variations in the alternating current power circuit voltage and means 'for introducing a surge voltage of short duration into the grid controlled circuit upon a variation in the power circuit voltage in a direction to increase the rate of correction of the regulated quantity.

12. In a regulating system, an alternating current power circuit, a dynamo-electric machine connected to said power circuit and havinga field winding, grid controlled rectifier means for supplying unidirectional current to said field winding, means for controlling the current output of said rectifier means comprising a grid controlled tube, a plurality of means in the grid control circuit of said tube including a filament cathode diode detector tube responsive to the voltage of said alternating current circuit and a pair of full wave rectifier means for developing unipotential voltages that are a measure of the voltage of said alternating current power circuit, means for introducing one of said rectifiedvoltages into the'grid circuit of said tube in a direction to cause a corrective action in the regulated voltage prior to the time required for the response of the diode tube, and means governed by the second full wave rectifier for introducing a. voltage surge of short duration into the grid controlled circuit of said tube in a direction to increase the rate of correction o the power circuit voltage.

13. In a regulating system, an alternating current power circuit, a dynamo-electric machine connected to said power circuit and having a field winding, grid controlled rectifier means for supplyingv a unidirectional currentto said field winding, means for controlling the current output of said rectifier means comprising a grid controlled tube, means for introducing a control voltage component into the grid circuit of said tube that varies promptly in accordance with variations in the regulated quantity to initiate a corrective action, and a cathode filament diode detector tube sensitive to the regulated quantity for recalibrating the grid controlled tube after its initial response to variations in the regulated quantity to insure an accurate final adjustment.

, FINN H. GULLIKSEN. 

